Conduritol Beta-epoxide, a saccharide that strongly inhibits Beta-glucosidases, was synthesized by a method developed by this section that provides the produce in greater yield than previously available and permits the preparation of this compound containing a tracer with extraordinarily high specific radioactivity. Administration of conduritol Beta-expoxide to animals produces a syndrome that resembles Gaucher's disease in humans by inhibiting the enzyme glucocerebrosidase. Radioactive conduritol Beta-epoxide reacts with the active site of glucocerebrosidase isolated from normal human tissues and from patients with Gaucher's disease. This use of the radioactive conduritol Beta-exposide will materially accelerate the identification of the amino acid substitutions (or deletions) that occur in the glucocerebrosidase molecule in patients with Gaucher's disease. Work was continued on the syntheses of glycolipid analogus of sphingolipids that yield a chromogenic moiety on enzymatic hydrolysis. These compounds are used for the diagnosis and studies of Niemann-Pick, Gaucher's and Krabbe's disease.